The present invention relates to a propulsion device for an agent contained in a cavity.
In order to propel a gaseous or liquid agent, devices for propelling agents contained in cavities are known and include at least a cap for filling the cavity with the agent, and a port for the agent to leave the cavity. The cap is configured to open when a pressure in the cavity sealed with the cap exceeds a calibrated pressure. In order to open the port, for example, configured as a breakage or rupture disk in the wall of the cavity, a pressure generator can be fastened watertightly to the cap, and hence to the cavity. The pressure generator induces by electrical triggering the propulsion of the agent through the port that breaks under the build-up of pressure caused by the pressure generator.
Such devices find applications in several areas, for example, in the field of extinguishing fire or cooling, depending on whether the agent is an extinguisher or a cooling agent. However, they can be used in other distinct areas that require propulsion or a fast and eventually important thrust of an agent out of its storage cavity. In the following description, reference is made mainly to the area of extinguishing fire or cooling, especially in the field of transportation, e.g., by means of an aircraft where several problems concerning the propulsion device for an extinguisher agent can be faced, for example, regarding safety (impact resistance, making sure of the proper triggering of the pressure generator, etc.), limitation of the device volume, weight, cost, etc.
Furthermore, it is important to be explicit in two aspects relating to the making or maintenance of a gas generator that acts as an initiator of the propulsion of the agent out of the cavity. The first aspect is due to the fact that the gas generator can be damaged or simply does not work anymore for an undetermined reason. This aspect may escape a maintenance ground crew and disrupt the fire extinction in the flying aircraft. Therefore it is important to propose a propulsion device that is easy and efficiently to control.
The second aspect relates to the use of a pressure generator containing as principal initiator an energy-type fuel like an ordinary pyrotechnic module. This type of pyrotechnic generator, in addition to its good propulsion efficiency, requires a complex and expensive technique of manufacturing to ensure it is reliable enough, especially in aeronautics where standards of security are very strict. If the cavity needs to contain a large quantity of an extinguisher agent, a required quantity of energy material can then be equally high. This requires high skills of manufacturing and of maintenance to ensure the device operates with a proper level of safety and reliability.